I thought of such delicious pieces of pop culture while watching "Galaxy Quest". The movie opens at a comic book convention, where the celebrity guests were performers in a very "Star Trek"-like TV show called, well, "Galaxy Quest". It was cancelled in the early 1980s, and now its actors are out of work, spending their time showing up at gigs to sign autographs. Main star Jason Nesmith (Tim Allen), who bears a suspicious resemblance to William Shatner, is a goofball who drinks too much and takes his fans' affections for granted. Blonde bombshell Gwen DeMarco (Sigourney Weaver) still laments that interviewers only ever asked her about her breasts. Classically-trained thespian Alexander Dane (Alan Rickman) is known for his moaning: "I played Hamlet once!" he wails into the mirror.

These guys, along with three other former cast members, run into some strange-looking fans who talk in robotic voices and make jittery movements. They make a plea of Jason, which he interprets as a request for another star appearance. As it turns out, though, this band of admirers are actually aliens who have seen and admired "Galaxy Quest" from outer space, believing it to be a set of historical documents. They want help from their heroes to battle their intergalactic foes.

After a period of initial shock, Jason excitedly leaps into this opportunity. "It'll be fun! Just like being on the show!" His colleagues have to take him aside to remind him that they are not real space warriors, just actors. Not a problem, it turns out: The friendly aliens' spaceships have been modelled on those of "Galaxy Quest", and the controls have been based on the actors' movements.

What I love about this movie is that it replicates the feel, structure and rhythm of sci-fi adventures with a rejuvenating sense of lightheartedness. In other words, it's as exciting as those old shows were from a kid's point of view, and very funny, too. The film has a lot of self-referential dialogue, but that's nothing new any more -- its general sense of whimsy is much more enjoyable. And it has a moment I've been waiting to see for years: Instead of the spaceship pulling out of its tiny loading bay with perfect ease, the pilot ends up bumping it against the wall, and having to say "Oops! Sorry!"

The cast is terrific. Tim Allen, Sigourney Weaver, Alan Rickman and Tony Shalhoub are familiar faces, and look so out of their depth in the middle of all this silliness that of course we find ourselves smirking. They also create characters we care about. Just because they're in a comedy doesn't mean they turn into robots who spit out one-liners -- they interact like real people, making everything they have to deal with just that little bit more absurd, and entertaining.